1. Field of the Invention
The invention relates to a method of precise positioning of a number of cooperating cylinder or roller elements of a roller or casting installation relative to each other. The invention further relates to a roller or casting installation with a plurality of cooperating cylinder or roller elements.
2. Description of the Prior Art
In continuous casting installation in particular, it is necessary to align as precisely as possible a number of cooperating roller elements relative to each other, with the roller elements forming, in an aligned condition, a casting bow for the cast metal strand.
In order to carry out the alignment, it is known to determine positions of separate roller element of a casting installation by measurement using theodolites, leveling instruments, profile batter boards. At that, primarily, a reference is made to reference marks associated with separate elements which do not remain stationary relative to the ideal measurement references line of the installation, i.e., as a rule, to the passing line of the rear edge of the strand (thermal expansion, foundation settlement). Each separate measurement provides, respectively, only two of three spacial coordinates of a measurement point. A complete determination of the measurement point in space is effected by cross-correlation that is carried out primarily manually with a tachymeter.
For control after an optical measurement, often, transitions between segments are measured again. At that, often, discrepancies appear between the expected results from the roller plan, i.e., between theoretical set positions, the produced measurement results, and the results of control measurement.
In order to achieve an optimal balance of separate positions of a cylinder or roller element (ideal position-measurement control), very high expenses become necessary. Typically, alignment of all of the roller elements of a continuous casting installation lasts about two weeks. Besides, erroneous alignment cannot always completely be avoided, which causes, as a result, quality problems and production constraints. Correspondingly high are follow-up costs of an unsatisfactory alignment of separate elements of a continuous casting installation.
In order to eliminate the discernable erroneous positions of the roller elements, in particular, the discernable errors caused by a so-called re-alignment, separate roller elements (segments) should be taken away with a crane or a manipulator and put at another location. Then, the positioning shim packages should be dismounted, exchanged, and be again mounted and secured.
Thereafter, the segment can be mounted back. Because often only one crane or manipulator is available, all of the segments should be aligned one after another. The time period per segment amounts to at least form two to three hours, wherein the alignment of up to fifteen segments per strand is necessary, in particular with a new construction or after a modification.
In FR 26 44 715, for alignment of a number of rollers of a casting installation, a laser beam is used, wherein the distance of separate elements of the installation to the laser beam is determined. The laser beam also serves as a quasi solder. A similar solution is disclosed in U.S. Pat. No. 4,298,281.
DE 101 60 636 A1 discloses a method of adjusting a casting gap in a strand guide of a continuous casting installation. In order to provide for a simple measurement, determination of defects, and malfunction-free start of casting, it is contemplated to adjust the casting gap before start of casting in accordance with an ideal course of the strand thickness with a positioning system. After the start of casting, the continuous and discontinuous point-free casting gap is adjusted under an operational load. Special measures for aligning of separate segments of the installation are not disclosed at this solution.
The measurement of distances of separate rollers along a casting bow for checking the alignment of rollers is disclosed in JP 55 070 706A.
U.S. Pat. No. 3,831,661 discloses that for alignment of separate segments of a continuous casting installation, the separate segments are provided with reference marks to which a gauge can be attached to be able to check the relative position of adjacent segments.
Other solution related to alignment of two machine parts, in particular, rollers relative to each other are disclosed in EP0 075 550 B1, EP 222 732 B1, EP0 867 649 B1, FR 2 447 764A, CH 583 598, DE-AS-27 20 116.
It should be pointed out that the drawbacks of conventional methods and associated therewith installations for aligning separate cylinder or roller elements of a roller or casting installation consists in that the necessary alignment time is very long, in particular, after modification or servicing of the installation. The availability of the installations is thereby low, which results in high operational costs. Further, the precision with which the alignment of separate elements can be carried out, is at least partially not satisfactory, which results in that the product quality is not optimal. Further, a non-optimal alignment of the elements relative to each other reduces reliability of the process and increases its susceptibility to errors.
Different solutions of state of the art bring only partially better results. Anyway, these are not satisfactory for a high-quality production or for a rapid and efficient alignment of cylinder and roller elements.